LR 308 Bolt Catch Question

[GSPKurt]

Is the screw that holds the bolt catch in the upper an allen head? Torx? What size? :help:

 

Thanks!

[EasyEJL]

Allen, but I can't recall the size and I'm not at the house to check

[edgecrusher]

Is the screw that holds the bolt catch in the upper an allen head? Torx? What size? :help:

 

Thanks!

I don't have a LR308, but most of the ones I have come across are 3/32 allen

[bruss01]

I am new to building AR rifles but have recently undertaken to build four of them.

 

The two AR-15's went together fine.  Under manual handling, operation is exactly by the book.

 

However, the two 308 builds (beautiful though they are) are having issues with the bolt catch.

 

I just built these 308 AR's and both of them are displaying the same behavior. The rifles have been assembled but have not been out to be fired yet, this is all just manually cycling the action.

For the record, the receivers are Sun Devil 308 (DPMS pattern) matched billet upper/lowers with nickel/teflon coating, the bolt is the JP Enterprises Low Mass, and the bolt catch is a 308-specific DPMS type bolt catch.

If I pull the charging handle back slowly with an empty mag inserted, I can *sometimes* get the bolt catch to engage. Also I can sometimes coax this engagement with a mag removed, while pressing on the bolt release ( the small end of course). This engagement is not reliable, with the bolt going forward unexpectedly more often than not.

Can anyone advise me on what/where to check to determine what is going on and how to remedy the issue? Thanks.

[GSPKurt]

The bolt catch will not engage if there is no magazine inserted.

 

It sounds to me as if the spring is weak or missing. You *did* install the spring, didn't you?

[Robocop1051]

The bolt catch will not engage if there is no magazine inserted.

It sounds to me as if the spring is weak or missing. You *did* install the spring, didn't you?

You should still be able to manually engage the bolt catch without a magazine. Not having the spring, or having a weak spring, shouldn't prevent the catch from engaging. In fact a spring issue usually causes the catch to prematurely engage.

The LR308 uses a standard AR15 bolt catch. Try using an Armalite AR10 bolt catch. The contact area has a little more "meat" to it. The JP LMOS may be a little small to grab the undersized catch.

I would suggest a new magazine, as this is happening on multiple rifles... But seeing that the parts are the same, and the OP says that he has issues even manually manipulating the catch, I'll stick with the suggestion for a AR10 catch.

This may also be a prime opportunity to upgrade to a Phase 5 Battery Assist lever. The 308 model comes with a bolt catch attached to the lever.

[GSPKurt]

 

This may also be a prime opportunity to upgrade to a Phase 5 Battery Assist lever. The 308 model comes with a bolt catch attached to the lever.

 

 

I have this installed on my LR308. I love it.

[survivalshop]

 

This the difference between an AR 15 catch & an LR 308 catch. Make sure you have at least a 308 catch for your 308 build . The AR 10 catch is a little better, but the LR 308 one works a whole lot better than putting a AR 15 catch in there.

With an AR 15 catch , it may not hold or catch the BCG at all. 

 

This is how it should look.

[GSPKurt]

<thumbsup>

[texas30cal]

I just realized that mine won't catch open and the problem is that it doesn't have that little ear on the front that the mag follower pushes up on. Don't remember where it came from but will be getting the Armalite part. Thank's for the pics survivalshop!